sounds like a daily stuff that the IT service fella encounters

maybe your dad is trying to use it like windows.
my mother had trouble with mac initially, i had to keep telling
her... its not windows, its not complicated, the instructions are
in plain english.
he used to do the same thing with windows..
he'd open everything his stupid friends send him and he managed
to destroy the old PC when a virus managed to write something
somewhere which basically disabled ALL anti-virus programs i tried
to put in..
i told him that since his friends gave the bloody virus to him,
he can continue to spread it to his friends...
then the viral load got so much it fried the HDD..
i'm not kidding...